naleraphael / bytejection Goto Github PK

Steps to reproduce this issue:

1. comment out the print function in demo/run_patched_module.py at line 61.
   

   bytejection/demo/run_patch_module.py

   Lines 59 to 62 in 67a9ca2

   	# Payload to be injected
   	def new_verification():
   	print('... Content has been modified ...')

2. add arbitrary code to make that function work normally. (just make sure there is no print function in it)
3. repeat the function call modified.foo() as line 73 more than 3 times.
   

   bytejection/demo/run_patch_module.py

   Lines 70 to 73 in 67a9ca2

   	# Check the output of modified function
   	print('--- modified version ---')
   	modified_mod = load_module_from_path('modified', osp.join(THIS_DIR, 'modified.pyc'))
   	modified_mod.foo()

4. execute demo/run_patched_module.py.

Result of execution:

• Ubuntu 18.04, Python 3.6.9 (with gdb):

--- modified version ---
foo
foo
foo
Fatal Python error: deletion of interned string failed
KeyError: ''eyError'

Current thread 0x00007ffff7fd7740 (most recent call first):
  File "/media/nale/Data/Users/nale/project/bytejection/demo/pkg/foobarbuzz/core.py", line 8 in foo
  File "run_patch_module.py", line 78 in main
  File "run_patch_module.py", line 90 in <module>

Program received signal SIGABRT, Aborted.
__GI_raise (sig=sig@entry=6) at ../sysdeps/unix/sysv/linux/raise.c:51
51	../sysdeps/unix/sysv/linux/raise.c: No such file or directory.

• Ubuntu 18.04, Python 3.7.4 (with gdb):

--- modified version ---
foo

Program received signal SIGSEGV, Segmentation fault.
PyFunction_NewWithQualName ()
    at /tmp/build/80754af9/python_1565725737370/work/Objects/funcobject.c:33
33	/tmp/build/80754af9/python_1565725737370/work/Objects/funcobject.c: No such file or directory.

Something related to importlib.util.MAGIC_NUMBER makes it failed to import generated .pyc file.

• Error message:

  File "demo/run_patch_module.py", line 77, in <module>
    main()
  File "demo/run_patch_module.py", line 72, in main
    modified_mod = load_module_from_path('modified', osp.join(THIS_DIR, 'modified.pyc'))
  File "demo/run_patch_module.py", line 42, in load_module_from_path
    mod = _load_module(name, path)
  File "demo/run_patch_module.py", line 31, in _load_module
    spec.loader.exec_module(mod)
  File "<frozen importlib._bootstrap_external>", line 724, in exec_module
  File "<frozen importlib._bootstrap_external>", line 1005, in get_code
  File "<frozen importlib._bootstrap_external>", line 467, in _classify_pyc
ImportError: invalid flags 1571323424 in 'modified'

• Value of flags is also different on Windows 7 (local environment) and repl.it:
  • Windows 7: Python 3.7.4 [MSC v.1915 64 bit (AMD64)]

    ImportError: invalid flags 1571323537 in 'modified'
    

  • repl.it: Python 3.7.4 [GCC 6.3.0 20170516]

    ImportError: invalid flags 1571323424 in 'modified'